angular2做tab页的问题

代码如下：我想做个tab页，目前这个方法有个缺点:
当路由跳到white页面,在刷新的时候.active又会回到orange的li标签，我该怎么改呢

export class WhiteLists{
    private selected_tab:string = 'Orange';
    constructor(){}
}
<ul class="nav nav-pills nav-justified settings-nav" role="pilllist">
        <li role="presentation" class="{{selected_tab == 'orange' ? 'active' : ''}}"><a [routerLink]="['Orange']" (click)="selected_tab = 'orange'">黄色</a></li>
        <li role="presentation" class="{{selected_tab == 'white' ? 'active' : ''}}"><a [routerLink]="['White']"  (click)="selected_tab = 'white'">白色</a></li>
        <li role="presentation" class="{{selected_tab == 'black' ? 'active' : ''}}"><a [routerLink]="['Black']" (click)="selected_tab = 'black'">黑色</a></li>
    </ul>